Understanding Household Mold
The growth of mold is common in Southern climates and can occur anywhere and typically appears as a black/gray, yellow, or green growth. Mildew is a fungus that spreads as microscopic spores are carried by the wind. When the spores land on a surface, they feed either on the surface itself or on organic airborne dirt and pollen that has accumulated on the surface. The growth of mildew/mold is encouraged by moisture, warmth, lack of air circulation and organic nutrients, and darkness. (North elevations of buildings are susceptible in particular.) Since the spores travel through the air, their behavior tends to be erratic. During rainy periods, the mildew can appear on previously unaffected areas.
If you have mold inside your home it's because there is moisture which shouldn't be there. We have high humidity in the South, but there are good ways to help control the humidity in your home through the use of dehumidifiers, or HVAC control systems for your current air conditioning systems. Humidity should be maintained at 45% to 50% inside to inhibit the growth of mold. If you are experiencing mold in unusual areas inside your home, then you have a moisture issue which should be investigated and resolved. Maintaining the temperature and the humidity in a home is important to the longevity of the wood floors, doors, trim, rate of expansion and contraction of many materials in a home, and indoor air quality. Drastic temperature and humidity changes in the internal environment of a home is not recommended.
It's important to maintain the exterior of your home by washing it on a regular basis as needed. A significant food source for mildew is pollen and dirt. If it is left on the surface whether it is on the roof shingles, stucco, brick, cypress, stone or other materials, with adequate moisture and shade, mold will take hold and grow and spread. The best way to extend the life of the exterior finishes of a home is with a regular washing (not high pressure). Consult a local paint store for the most current additives for proper washing, and suggestions or contact us for a recommendation. The longer you wait and leave the mold and mildew unattended, the more it will deteriorate the finish and life of many of these materials. Many cleaners and preventatives of mildew growth, like "Mildew-Check by PPG", and "Olympic Mildew Check" do an excellent job of cleaning and/or preventing the growth of mildew and mold. See the NAHB Mold Tips for further information.
Always maintain a clean exterior free of vine growth and plant growth. Plants too close to the exterior structure of the home can create a restriction of air circulation around the materials of the home and thereby contribute to excessive growth. The look of vines and other plant materials may be nice, but the damage caused by such a look can be serious to the water proof barrier, window seals, and seals between similar and dissimilar materials, while creating a prime environment for mold and mildew.
Prior to cleaning any roofs, it's important to check with the manufacturer of your shingles to verify how exterior cleaning may affect your roof warranty. Most shingles contain mildew inhibitors, and over time, these inhibitors loose their ability to protect your roof from mold damage. There are products that can help keep your roof clean of mold and mildew through the application of inhibitors or installation of zinc strips type products.
- Regularly inspect exteriors and interiors for leaks and wetness
- Keep relative humidity levels inside at 45 to 50%
- Wash exteriors of buildings regularly or as needed
- Make sure landscape sprinklers are not repeatedly spraying the exterior finishes of your home
- Regularly Treat areas of mold growth with approved cleaning solutions and methods to remove the growth
- Apply mildew inhibitors after the surface is cleaned
- Call professionals when you're not sure what to do
